The present invention relates to an air feeding device for an endoscope, and in particular, to a safeguard system of an air feeding device.
Conventionally, an air feeding device for an endoscope has been known. The air feeding device has an air compressor which compresses the air within a sealed space, and by opening/closing a valve connected to the sealed space, the air is fed to the human body cavity through a tube such as a forceps channel of an endoscope. In such an air feeding device, an operator sets a desired pressure of the air in advance, and the air compressor and the valve are controlled such that the actual discharge pressure meets the pressure set by the operator.
If the compressor, the valve, or an electric circuitry malfunctions during operation, the pressure of the sealed space may become extremely high. If the air leaks from the sealed space, the pressure within the sealed space remains low and may not reach the pressure enabling the desired discharge pressure.
If the abnormal conditions as above are not appropriately dealt with, the following problems would occur: if the pressure of the sealed space is extremely high, the sealed space may be deteriorated due to a high pressure, or the human cavity may be destroyed due to a high discharge pressure of the air; and if the air leaks from the sealed space, the air feeding device itself may be broken since the pressure within the sealed space remains low even if the compressor is driven for a long period.
It is therefore an object of the invention to provide an air feeding device for an endoscope, for preventing the abnormal condition of the air feeding device.
For the above object, according to the present invention, there is provided an air feeding device for an endoscope, which is provided with:
a pressure control system that controls a pressure of air within a sealed space so as to fall within a predetermined set range;
an abnormal condition detecting system that detects an abnormal condition of at least one of the pressure within the sealed space and control of the pressure control system;
a resolving system that resolves the abnormal condition when the abnormal condition detecting system detects an abnormal condition.
Since the resolving system immediately resolves the abnormal condition, a dangerous condition, e.g., a condition where a human cavity is exposed to a danger can be avoided.
In particular case, the abnormal condition detecting system may detect whether the pressure within the sealed space exceeds a predetermined upper limit.
It is preferable that, in the above case, the upper limit is a maximum pressure of a pressure range at which the air discharged from the endoscope would not hurt a human cavity.
Optionally or alternatively, the abnormal condition detecting system may detect whether the pressure control system controls the pressure within the sealed space to fall in the predetermined set range within a predetermined period of time.
When the abnormal condition is detected, the resolving system decreases the pressure within the sealed space. Since the pressure in the sealed space is decreased regardless of the type of the abnormal condition, a human cavity may not be exposed to danger.
Optionally, the resolving system terminates operation of the air feeding device. Therefore, the air feeding device may not be broken due to the abnormal condition.
Optionally, the air feeding device may be provided with a warning system that indicates occurrence of the abnormal condition.
The warning system indicates the occurrence of the abnormal condition by sound, by light and/or by displaying characters.
When the abnormal condition is indicated by displaying the characters, a type of the occurred abnormal condition may be indicated.
According to another aspect of the invention, there is provided an air feeding device for an endoscope, which is provided with:
a compressing system that compresses air within a sealed space;
a pressure measuring device that measures a current pressure of the sealed space;
a pressure control valve provided between the sealed space and outside, a pressure within the sealed space being decreased by opening the pressure control valve;
a pressure control system that controls the compressing system and the pressure control valve so that the pressure within the sealed space falls within a predetermined set range;
an abnormal condition detecting system that detects an abnormal condition of at least one of the pressure within the sealed space and control of the pressure control system; and
a resolving system that resolves the abnormal condition when the abnormal condition detecting system detects an abnormal condition.
Optionally, the pressure control system controls the pressure control valve to open when the pressure within the sealed space is greater than an upper limit of the predetermined set range, and wherein the pressure control system controls the compressing system to compress the air within the sealed space if the pressure within the sealed space is less than a lower limit of the predetermined set range.
Further, the resolving system controls the pressure control valve to open when the abnormal condition detection system detects the abnormal condition.
Furthermore, the resolving system controls the compressing system to stop compressing the air within the sealed space.